With society turning increasingly to sustainable development, sharper demands are being made concerning energy efficiency and other properties that mean reductions in the negative effects of the building on the environment and people. This means that architects must have a suitably adapted solution already in the early design phase, as this has the greatest influence on the final result. Current tools and methods used for this are either focused only on individual topics or are too complex and not adapted for independent use by architects. The paper presents a simplified method for evaluating building sustainability (SMEBS) which addresses these needs. It is intended as a tool to aid architects in the early project planning phases as it allows a quick evaluation of the extent to which the demands of sustainable building are fulfilled. The method was developed on the basis of a study of international building sustainability assessment methods (BSAM) and standards in this field. Experts in sustainable construction were invited to determine weights for assessment parameters using the analytical hierarchy process (AHP). Their judgments reflect the specific characteristics of the local environment.
14 August 2019 in International Journal of Polymer Analysis and Characterization
Amount of wood flour was gradually increased from 0 to 50 wt% in the production of polylactic acid (PLA) based filaments with 1.75 mm diameter using twin screw extruder. Surface roughness and wettability were measured of the specimens. Surface roughness of the specimens significantly increased with incorporation of wood flour into PLA filament. Wettability of the specimens significantly decreased with increasing wood flour content. This was mainly attributed to the higher surface free energy of PLA than the beech wood. Contact angle values of the 3D printed wood/PLA specimens having wood flour content up to 30 wt% were less than 90°.
Additive manufacturing is becoming increasingly important for manufacturing end products, not just prototyping. However, the size of 3D-printed products is limited due to available printer sizes and other technological limitations. For example, making furniture from 3D-printed parts and wooden elements requires adequate adhesive joints. Since materials for 3D printing usually do not bond very well with adhesives designed for woodworking, they require special surface preparation to improve adhesion. In this study, fused deposition modelling (FDM) 3D-printed parts made of polylactic acid (PLA), polylactic acid with wood flour additive (Wood-PLA), and acrylonitrile-butadiene-styrene (ABS) polymers were bonded to wood with polyvinyl acetate (PVAc) adhesive. The surfaces of the samples were bonded as either non-treated, sanded, plasma treated, or sanded and plasma treated to evaluate the effect of each surface preparation on the bondability of the 3D-printed surfaces. Different surface preparations affected the bond shear strength in different ways. The plasma treatment significantly reduced water contact angles on all tested printing materials and increased the bond tensile shear strength of the adhesive used. The increase in bond strength was highest for the surfaces that had been both sanded and plasma treated. The highest increase was found for the ABS material (untreated 0.05 MPa; sanded and plasma treated 4.83 MPa) followed by Wood-PLA (from 0.45 MPa to 3.96 MPa) and PLA (from 0.55 MPa to 3.72 MPa). Analysis with a scanning electron microscope showed the smooth surfaces of the 3D-printed parts, which became rougher with sanding with more protruded particles, but plasma treatment partially melted the surface structures on the thermoplastic polymer surfaces.
This work was motivated by a study of particle size effects on pyrolysis kinetics and models of polystyrene particle. Micro-size polystyrene particles with four different diameters, 5, 10, 15, and 50 µm, were selected as experimental materials. Activation energies were obtained by isoconversional methods, and pyrolysis model of each particle size and heating rate was examined through different reaction models by the Coats–Redfern method. To identify the controlling model, the Avrami–Eroféev model was identified as the controlling pyrolysis model for polystyrene pyrolysis. Accommodation function effect was employed to modify the Avrami–Eroféev model. The model was then modified to f(α) = nα0.39n − 1.15(1 − α)[−ln(1 − α)]1 − 1/n, by which the polystyrene pyrolysis with different particle sizes can be well explained. It was found that the reaction model cannot be influenced by particle geometric dimension. The reaction rate can be changed because the specific surface area will decrease with particle diameter. To separate each step reaction and identify their distributions to kinetics, distributed activation energy method was introduced to calculate the weight factor and kinetic triplets. Results showed that particle size has big impacts on both first and second step reactions. Smaller size particle can accelerate the process of pyrolysis reaction. Finally, sensitivity analysis was brought to check the sensitivity and weight of each parameter in the model.
Stakeholder communication plays an important role in enhancing the societal sustainability and business acceptability of the forest sector. The purpose of this study is to present the current state of forest sector communication research with its stakeholders at different hierarchical levels of sustainability (i.e., societal, sectorial, corporate, and product sustainability) in Europe.